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The article provides an overview of a study by P. S. Rand et al. that won the Robert L. Kendall Best Paper in the periodical "Transactions of the American Fisheries Society" in 2007. The researchers examined the potential effects of changing water discharges and warming water temperatures on adult sockeye salmon swimming upstream to spawn in the Fraser River, British Columbia. They have determined that declining river flows would offset the increased energy requirements of warmer water temperatures.

Over the past 35 years, the Upper Penticton Creek (UPC) Watershed Experiment has supported forest hydrology research in south‐central British Columbia (BC), Canada. This paper provides a synthesis of research results, highlights the challenges facing UPC and identifies new research directions. Clearcutting approximately 50% of two small, snow‐dominated (Dfb Koppen classification) watersheds advanced the timing of snowmelt‐generated high flows and decreased late‐summer low flows, relative to predictions based on pre‐treatment regressions. Changes in high flows did not have a significant effect on stream channels due to low stream power, coarse substrate, and limited riparian disturbance. Changes in summer low flows reduced modelled useable fish habitat by 20%–50%. Evaporation averaged 52% of the annual precipitation in the mature forest, was reduced to 30% in a clearcut, and recovered to 40% and 47% in a 10 and 25 year‐old stand, respectively. Groundwater recharge to the bedrock was estimated at 19% of annual precipitation, indicating that, even with the large uncertainty associated with this estimate, deep groundwater should not be ignored in the water balance. Suspended sediment, turbidity, and colour increased post‐logging; however, chemical surface water quality did not change. Aquatic community structure changed post‐logging; and although this affected the processing of organic matter, the effects on habitat quality were considered minimal. The information gained at UPC has supported provincial policies, management guidelines, forest stewardship plans and watershed risk assessments. The undisturbed control watershed, re‐growing treatment watersheds and ongoing long‐term hydrometric monitoring continue to provide opportunities for future research addressing issues such as the effects of young forests on streamflow and hydrologic recovery, and the influence of climate change on the hydrologic regime. [ABSTRACT FROM AUTHOR]

The paired watershed experimental (PWE) approach has long been used as an effective means to assess the impacts of forest change on hydrology in small watersheds (<100 km2). Yet, the effects of climate variability on streamflow are not often assessed in PWE design. In this study, two sets of paired watersheds, (1) Camp and Greata Creeks and (2) 240 and 241 Creeks located in the Southern Interior of British Columbia, Canada, were selected to explore relative roles of forest disturbance and climate variability on streamflow components (i.e., baseflow and surface runoff) at different time scales. Our analyses showed that forest disturbance is positively related to annual streamflow components. However, this relationship is statistically insignificant since forest disturbance can either increase or decrease seasonal streamflow components, which eventually limited the positive effect on streamflow at the annual scale. Interestingly, we found that forest disturbance consistently decreased summer streamflow components in the two PWEs as forest disturbance can augment earlier and quicker snow‐melt processes and hence reduce soil moisture to maintain summer streamflow components. More importantly, this study revealed that climate variability played a more significant role than forest disturbance in both annual and seasonal streamflow components, for instance, climate variability can account for as much as 90% of summer streamflow components variation in Camp, suggesting the role of climate variability on streamflow should be highlighted in the traditional PWE approach to truly advance our understanding of the interactions of forest change, climate variability and water for sustainable water resource management. [ABSTRACT FROM AUTHOR]

The Upper Penticton Creek watershed experiment has collected 28 years of streamflow data from 2 small snow-dominated watersheds on the Okanagan Plateau of British Columbia, where the effects of timber harvesting on streamflow regime are of broad concern. We apply 3 empirical analysis techniques to these data to evaluate changes in streamflow regime following clear-cut logging of 47% of the 241 Creek watershed, with the adjacent 240 Creek watershed serving as an unlogged control. While logging had only a small effect on annual yield (5% increase), the results of all 3 analysis techniques confirmed a dramatic change in the timing and magnitude of April through June streamflow. A paired watershed analysis showed that during the first 7 years post-logging, average April and May water yield increased by 29% and 19%, respectively, while June and July water yield decreased by 23% and 17%, respectively. This pattern of change was confirmed by significant increases in standardised April-May monthly total water yield. Changes in the daily flow duration curves for each month also show a 67% increase in daily yields exceeded ≤10% of the time in April and a 15% increase in May. Daily yields exceeded ≤10% of the time decreased by 24% in June and 17% in July. These streamflow shifts increase the risk of channel destabilization and damage to aquatic habitat during the snowmelt season, and water shortages in the Okanagan region early in the irrigation season (June through July). [ABSTRACT FROM AUTHOR]

Hydrologic modelling has been applied to assess the impacts of projected climate change within three study areas in the Peace, Campbell and Columbia River watersheds of British Columbia, Canada. These study areas include interior nival (two sites) and coastal hybrid nival-pluvial (one site) hydro-climatic regimes. Projections were based on a suite of eight global climate models driven by three emission scenarios to project potential climate responses for the 2050s period (2041-2070). Climate projections were statistically downscaled and used to drive a macro-scale hydrology model at high spatial resolution. This methodology covers a large range of potential future climates for British Columbia and explicitly addresses both emissions and global climate model uncertainty in the final hydrologic projections. Snow water equivalent is projected to decline throughout the Peace and Campbell and at low elevations within the Columbia. At high elevations within the Columbia, snow water equivalent is projected to increase with increased winter precipitation. Streamflow projections indicate timing shifts in all three watersheds, predominantly because of changes in the dynamics of snow accumulation and melt. The coastal hybrid site shows the largest sensitivity, shifting to more rainfall-dominated system by mid-century. The two interior sites are projected to retain the characteristics of a nival regime by mid-century, although streamflow-timing shifts result from increased mid-winter rainfall and snowmelt, and earlier freshet onset. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Within an area where the regional climate variability signal is apparent, local factors including location, topography and land characteristics affect hydrological response to the signal. Mountainous areas, such as the Western Cordillera in North America, are expected to possess such local effects. The Fraser River Basin in British Columbia, Canada, contains stations with 40 years of precipitation and discharge records from stations widely distributed across the 217 000 km2 basin. Correlation coefficients were calculated to relate winter precipitation, spring and summer high flow to several climate indices: Pacific Decadal Oscillation (PDO), Pacific-North American (PNA) and Southern Oscillation Index (SOI). Analyses confirmed that the level of correlation changes during the snowmelt period and does vary locally within the Basin. Correlation of discharge with the indices also changes along the Fraser River, being strengthened or weakened by the influence of its tributaries. These results caution that in hydrologic investigations, (1) even where the region as a whole manifests a strong teleconnection signal, deviation in signal strength within a medium-sized basin causes local variations in streamflow response to the regional climatic forcing, and (2) the level of correlation attained by streamflow at a basin outlet does not necessarily apply to its tributary sub-basins. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The article presents the research study on the groundwater responses in temperate mountainous terrain using the data including groundwater, hydrometric, and climatic aspects from southern British Columbia. It discusses the hydroclimatology of the region focusing on the rainfall-dominated, snowmelt-dominated, or mixture of rain and snow which affects the rechardge and discharge response of the groundwater. It proves the efficacy in determining the hydrogeologic and hydroclimactic forecast.

Examines the shallow hillslope groundwater as a dominant source of streamflow in sloping bog-forest uplands of the North Coast Forest District in British Columbia. Estimated mean residence time of water; Analysis of the baseflow discharge and isotopic response; Use of dissolved organic carbon and deuterium excess as hydrological tracers.